Tencent meeting link:  https://meeting.tencent.com/dm/LMJYrcxi7TBX     Meeting ID:  854671043, no password

Abstract:

In the iron-based superconductor Fe(Te,Se), a topological phase transition is expected by changing Te/Se compositions, and it is considered a promising route to manipulating the topologically superconducting states and Majorana zero modes. In this talk, I will report our recent work on the electronic structures of FeTexSe1−x single crystals over a wide Te/Se composition range using high-resolution angle-resolved photoemission spectroscopy. We provide the first direct demonstration of the band inversion along the kz-axis, and further resolve the topological phase transition directly from the band structure. More importantly, our high-resolution measurements reveal that a special Te/Se composition exists, at which the Dirac point is located exactly at the Fermi level. This is essential for realizing clean and isolated Majorana zero modes in vortex cores. 

Biography:

Peng Zhang is a professor at the School of Physics, Nanjing University. He obtained his Ph.D. from the Institute of Physics, Chinese Academy of Sciences. From 2016 to 2021, he conducted research at the Institute for Solid State Physics, University of Tokyo, and was awarded JSPS Postdoctoral Fellowship in 2019. He joined Nanjing University in 2021. His research focuses on topological superconductivity, unconventional superconductivity, and topological materials using high-resolution angle-resolved photoemission spectroscopy.